I've now re-tuned a set of five Lucky 13s (G, A, C, D and F) to the tuning shown in "2018-03-05 (3).png" above. The most difficult part, as expected, was lowering the 7 draw by two semitones, so that it would match the 6 draw.

The tuning works well. I expect it will be especially useful when playing many kinds of pop/rock. However, the total lack of dominant seventh chords leaves the whole tuning sounding a little bit "white bread." For more bluesy tunes, this would probably sound a little too plain.

My current thinking is that this basic re-tuning for a Richter or double-Richter harp can be modified to enable each of the I, IV and V chords the option of being played in their dominant seventh forms. I will diagram this later, but for now, a verbal description:

Three differences from the "2018-03-05 (3).png" diagram above:

1. The 7 blow would be lowered by two semitones and another 31 cents (in this example, from C to septimal minor B-flat). This gives the flanking IV chords the option of being played as dominant sevenths.

2. The 5 draw would not be re-tuned to a new note. It would, however, be lowered by 31 cents, to become a septimal minor seventh of the I chord. In this way, the I chord to its left (i.e. the 1-4 draw Gmaj) can retain its stock option of being played as a dominant seventh.

3. The 7 draw would be raised from its stock tuning by just one semitone minus another 31 cents (in this example, from B to septimal minor C). This gives the V chord to its right (i.e. the 8-10 blow Dmaj) the option of being played as a dominant seventh. As a bonus, this re-tuning of just one semitone is easier and more reliable than my original plan of altering this reed by two semitones.

Fortunately, I recently purchased two inexpensive Easttop 10-holers (the K and the S models) and can give this a try without too much risk. I will report back.

Last edited by IaNerd on Mon Mar 26, 2018 4:41 pm, edited 2 times in total.

I just re-tuned a K-type 10-hole Easttop of the key of C, as per the post just above. Only four reeds needed to be re-tuned--three of them to "septimal minor seventh", i.e. ET -31 cents. For information on the rationale of that choice, see viewtopic.php?f=9&t=198 .

My initial impression is that it works the way I intended it to, and it will be a better tool for situations that call for dominant sevenths of the I, IV and V chords.

My two reasons for choosing the bottom c is that with this choice it is easier to play melodies, and that it is very out of the way when you don't use it. You could play all the normal I-IV-V-stuff with nice big chords, and then add in the minor vi when it's needed.

(PS: I see people here seem to mainly use Roman numerals to describe chords. I often talk in terms of tonics, minor parallels, subdominants and such, and some times I mix the two. If I do, will people understand me? It would not be a problem to use either one system exclusively if that makes it clearer.)

Intrigued by Brendan's new Overblow Booster technology, I asked him if that tuning could work with a specially-prepared Booster. He said that it probably could, but then there would be an additional charge for developing a special product. He further suggested that some modifications to that basic tuning could bring it into a "regular breath pattern", i.e. where each draw reed is higher than its corresponding blow reed of a chamber.

An Overblow Booster that Brendan is already developing for "regular-breath" harps, like PowerDraw and PowerBender, could be used on pretty much any harps with a regular-breath pattern. That makes overblows possible across all ten blow notes.

We discussed this matter back and forth a couple of times. This is perhaps the best result (so far) that came from the discussion: